| Mixels | February 12, 2014 | Cartoon Network | 31 |
| Miś Kudłatek | — | — | — |
| Moby Dick and Mighty Mightor | September 9, 1967 | CBS | 18 |
| Moby Dick and the Secret of Mu | April 16, 2005 | TF1 | 26 |
| Mofli, the last koala | September 3, 1987 | Televisión Española | 13 |
| Moka's Fabulous Adventures! | January 4, 2020 | Gulli | 78 |
| Molang | January 2, 2016 | Disney Jr. | 306 |
| Mole’s World | — | — | — |
| Molly of Denali | July 15, 2019 | PBS, PBS Kids | 67 |
| Momo | November 3, 2003 | — | 26 |
| Momonsters | March 20, 2020 | Clan | 104 |
| Mona the Vampire | September 13, 1999 | YTV | 65 |
| Monchhichis | — | American Broadcasting Company | 13 |
| Mongo Wrestling Alliance | January 23, 2011 | Adult Swim, Cartoon Network | 10 |
| Monk Little Dog | June 16, 2009 | Canal+ | 52 |
| Monkart: Legend of Monster Kart | August 28, 2017 | — | 26 |
| Monster Allergy | December 19, 2005 | ZDF, BBC One, Antena 3, Cartoon Network, Rai 2, YTV, M6 | 26 |
| Monster Buster Club | June 2, 2008 | Jetix, Gulli, YTV | 52 |
| Monster Farm | 1998 | — | — |
| Monster High | October 6, 2022 | Nickelodeon | 33 |
| Monster List | — | Bilibili, IQIYI, Tencent Video | — |
| Monster Mania | September 11, 1995 | Broadcast syndication, CITV | 26 |
| Monster Math Squad | May 7, 2012 | CBC Kids | 50 |
| Monster Shaker | July 8, 2024 | Gulli, Clan | 51 |
| Monster Top | — | KBS 2TV | — |
| Monsters & Pirates | 2009 | — | — |
| Monsters at Work | 2021 | Disney+ | 20 |
| Monsters vs. Aliens | March 23, 2013 | Nickelodeon | 26 |
| MooBoo Cops | — | Kaku Children's Television | — |
| Moominvalley | 2019 | Yle | 26 |
| Moon Girl and Devil Dinosaur | February 10, 2023 | Disney Channel | 30 |
| Moonbeam City | September 16, 2015 | Comedy Central | 10 |
| Moonzy | September 1, 2006 | Russia-1, Russia-K, Carousel, Mult | 572 |
| Moral Orel | December 13, 2005 | Adult Swim | 43 |
| Moriki-Doriki | 2018 | — | 26 |
| Mork & Mindy/Laverne & Shirley/Fonz Hour | September 25, 1982 | American Broadcasting Company | 27 |
| Mort and Phil | January 14, 1995 | Antena 3 | 26 |
| Mortal Kombat: Defenders of the Realm | September 21, 1996 | USA Network | 13 |
| Mot | May 30, 1995 | Canal+, France 3 | 26 |
| Motel Transylvania | 2025 | Netflix | — |
| Mother Goose and Grimm | September 14, 1991 | CBS | 10 |
| Motorcity | April 30, 2012 | Disney XD | 20 |
| Motown Magic | November 20, 2018 | Netflix | 25 |
| Motu Patlu | October 16, 2012 | Nickelodeon India | 1,296 |
| Mouk | September 19, 2011 | France 5 | 104 |
| Mountain of Gems | 2005 | — | 71 |
| Mouseterpiece Theater | April 18, 1983 | Disney Channel | 60 |
| Mouss & Boubidi | June 29, 2009 | ICI Radio-Canada Télé, France 3, France Ô | 52 |
| Moville Mysteries | September 7, 2002 | Nickelodeon | 26 |
| Mr Benn | January 7, 1971 | — | 14 |
| Mr. Baby | May 3, 2009 | France 3 | 48 |
| Mr. Bean: The Animated Series | January 5, 2002 | ITV1 | 130 |
| Mr. Bogus | January 1, 1991 | Broadcast syndication | 58 |
| Mr. Hiccup | 1983 | — | 39 |
| Mr. Magoo | May 4, 2019 | — | 78 |
| Mr. Pickles | September 21, 2014 | Adult Swim | 20 |
| Ms. Black-Rose's Stationery Store | — | MBC TV | 52 |
| Muddle Earth | March 15, 2010 | CBBC | 26 |
| Muddy the Little Master | — | Golden Eagle Cartoon | 26 |
| Mulligan | May 12, 2023 | Netflix | 10 |